Gripper for the tops of bags, sacks, and the like



y 17, 19.51 I H. ANDERSON 2,561,306

GRIPPER FOR THE TOPS OF BAGS, SACKS AND THE LIKE Filed April 10, 1947 2Sheets-Sheet 1 I l C9 28 ?E o m 2 8 I l8 2 l2 IL )3 54 80 I4. I 76 58 11o o [H a 44 o o a 52 INVENTOR HELMER ANDERSON BY W ATTY

July 17, 1951 GRIPPER FOR THE TOPS OF BAGS,

Filed April 10, 1947 H. ANDERSON SACKS AND THE LIKE 2 Sheets-Sheet 2HELMER ANDERSON Patented July T7, 1951 GRIPPER FOR THE TOPS OF BAGS,SACKS, AND THE LIKE Helmer Anderson, Minneapolis, Minn., assignor toGeneral Mills, Inc., a corporation of Delaware Original application May13, 1943, Serial No. 486,918. Divided and this application April 10,1947, Serial No. 740,689

This invention relates to grippers for holding sheets by their upperedges, such as the open tops of bags, sacks, and the like.

An object of this invention is the provision of means for readilygripping the open opposite top sides of the sack or bag, particularlypaper bags, preferably at the center so as to hold the same suspendedvertically.

Another object is to provide gripping means which will increase the gripdue tothe weight of the bag and contents.

Still another object is the provision of gripping members which areeccentrically mounted with respect to each other so that a straightdownward pull on the sheet gripped tends to move the gripping memberstoward each other thereby bringing them closer together and increasingthe grip on the object.

These, and other objects as will hereinafter appear, are accomplished bythis invention which is fully described in the following specificationand shown in the accompanying drawings, in which Figure 1 is a partialside elevation showing the top of a machine embodying this invention;

Fig. 2 is an end elevation of the same;

Fig. 3 is a partial enlarged vertical elevation of the bag grippersshowing the gripper plates in process of gripping a bag but not lockedat the entering end of the machine; and

Fig. 4 is the same with the gripper plates locked and about to bereleased at the head end of the machine.

This is a division of my copending application, Serial No. 486,918,filed May 13, 1943, entitled, Compacting Flour in Bags, now Patent No.2,419,330.

The embodiment herein illustrated comprises four vertical corner postsor standards I I, I2, I3, and I4 which are secured at the bottom to abase not shown and at the top to a top casting I5.

A carriage I5 is slidably mounted at these four corners on the fourvertical posts and may be raised and lowered thereon by means of fourscrew-threaded shafts I8 which are threaded through suitable blocks 20on the sides of the carriage and are journalled in bosses 22 inthe sidesof the top casting I5. These shafts are provided at their tops withbevel gears 24 which mesh with bevel gears 26 on shafts 28 which areconnected by suitable similar sprockets 30 which in turn are connectedby a chain 3 I. One of the shafts 28 is provided with a crank handle 32as shown in Fig. 2. By turning this the carriage I6 may be raised andlowered as desired with a parallel motion. I

11 Claims. (Cl. 248-99) A motor M is preferably mounted on the topcasting I5 and has a belt for driving the mechanism as shown in theoriginal application of which this is a division. It is not necessary,however, that this drive be shown herein as it forms no part of thepresent invention.

A head shaft 49 (Fig. 1) is suitably journalled in bearings 42 in thecarriage I5 and carries a bevel gear 44 which is driven by a bevel gear46.

The latter is an integral part of a sleeve 48 which I is journalled in avertical bearing 50 and which is internally splined to receive a splinedshaft 52 which is driven in any suitable manner. While the shaft 52rotates, it has substantially no endwise movement, whereas the sleeve 48and. bevel gear 46 move up and down with the carriage I6. Motion is thustransmitted to the head shaft 49 and this shaft drives spaced sprockets54 in a counterclockwise direction and which in turn drive the spacedchains 56 which pass around the tail sprockets 58 which are mounted on asuitable shaft 60, the tension in the chain 56 being adjusted by meansof adjusting screws 92.

Flights I0 are carried on the chains 56 as shown particularly in Figs. 3and 4, and each flight is provided with two laterally extending rollers12 at each end which are journalled on suitable pins I4. These rollersroll on parallel tracks I6 above and I8 beneath, which in turn arecarried on suitable brackets 89, 82 respectively from the carriage I6.

Plain gripper jaws 95, 96 are carried by levers 91, 98 which in turn arecarried on shafts 99, I00 suitably journalled in the flight Ill. Onsimilar shafts IOI, I92 are mounted other levers on which are carriedcorrugated gripper jaws I03, I04. The jaw I93 is pivotally mounted atI95 on a bell-crank I06 which in turn is pivotally mounted at I91. Theopposite end of the bell-crank is pivotally connected to a short eyeboltI08 which passes through a lever I09 and is adjustably secured by meansof lock nuts IID. This eyebolt is normally pressed inwardly by means ofa compression spring III. The pin I9! is carried on the lower end of alever IIZ which is rotatably mounted on the shaft IUI and carries ashoulder H3 against which the upper end of the corrugated gripper jawI03 is slidable and suitably guided. The upper end of the lever H2 ispivotally connected to a link II4 by means of a pin I I5. The oppositeend of the link I I *4 is pivotally connected to the upper end of thelever 98 by means of a pin I I6.

The levers 91 and I I2 are caused to oscillate in opposite directions bymeans of meshing seg- H mental gears. The upper end of'the corrugatedgripper jaw I03 is held against the shoulder II3 by means of a springIll. The levers 98 and H2 are normally urged in a clockwise direction bymeans of a tension spring I I8.

The link H4 is hollow and has an adjustable locking block II9 mountedtherein and adjustably secured by means of bolts I20. This block has ashoulder I2I which is adapted to be engaged by the outer end of alocking finger I22 mounted on a shaft I23 which is suitably journalledin the flight 10 and which carries a release lever I24.

The operation of this intermittent feed bag gripper is as follows. Withthe jaws 95, 9B. and I03, I04 separated, as shown in- Fig. 2, the bag orobject to be gripped is raised as shown in dotted lines in Fig. 1 inwhich position the top of the bag comes between open operating pairs ofgripping jaws at the two sides of the bag. A latching lever I30, whoseconstruction and operation will later be described, presses the link II4to the left thereby rocking the levers 91 and H2 toward each other andmoving the locking jaws into adjacent position as shown in Fig. 3. Afurther movement of the link I I will cause the gripping jaw I03 toslide down with respect to the jaw- 95, as shown in Fig. 4, therebycausing an ear I25 to slide down over the inclined upper portion I25 ofthe jaw Q5, thereby firmly locking together the jaws st and Iiit. Afurther movement of the link IM under pressure of the lever I30 willcause the bell-crank I05 to rock in a clockwise direction about the pinI? thereby lowering the jaw I03 with respect to the jaw 95 as shown inFig. 4. At the same time the shoulder I2I passes beyond the lockingfinger I22 which lifts into position behind the shoulder I2I by theaction of spring mm which is attached to the end of a depending arm onthe lever I24, thereby locking the parts of the gripper in grippingposition. At the same time the lever 08 moves to grip the top: of thebag between the grippers 9B and H34 in the same way and by a similarsystem of levers which are largely duplicate parts and hence have notbeen described in detail.

The weight or" the bag serves to further tighten the hold of thegrippers on the bag. Thisis accomplished by making the jaws slidablewith respect to each other and by roughening or corrugating the innersurface of the outer or movable jaw W3 while the inner surface of thejaw 95 is smooth. The movable jaw will tend to move with the paper.Thus, the jaw I 03 is pivotally mounted on thebell-crank Iiitwhichswings about the pin [37. Any downward movement of" the jaw I03, asshown by the difierence in positions of the jaws 95 and I03 in Figs. 3and l results in a toggle action of the bell-crank Hi8 which brings amuch greater pressure between the jaws 9:: and I03. The inside of thejaw is made smooth to prevent damage to the inner liner of multi-wallbags which are often of much thinner material than the outer Walls ofthe bag. The corrugations on the jaw Hi3 are not sharp enough to cut ortear the outer walls.

The mechanism for locking and unlocking the grippers is fully describedinmy original application Ser. No. 486,918 and will not be duplicatedherein. It consists primarily of a lever I30: (Fig. 3) which forces thelocking block H9 to the left when the latter reaches a predeterminedpoint in its travel thereby closing. the pairs of gripper jaws 05; I63and 06, I0 1 on has top or other object placed between. them. Thegripper. jaws are firstopen wide as shown in Fig. 2 andas- 4 the flightI0 comes beneath the center line of the tail sprockets 58 the lever I30forces the gripping jaws nearly closed as shown in Fig. 3 and then intothe fully closed position of Fig. 4 wherein the lockingfinger I22 isheld on the shoulder I2 I.

the flight approaches the head end of the machine a lever I60 strikesthe release lever I24 releasing the finger I22 while the spring II8 ofFig. 4 returns the gripper jaws to the open position shown in Fig. 2.This releases any bag or other object held by the grippers.

While the foregoing description and drawings apply particularly togripping the opposite top edges of bags, it is apparent this gripper isnot necessarily limited to this particular application.

Thus, it will be seen I have provided a simple but efficient means forgripping the open top of a bag or other flat object held between thegrippers.

While I have shown and described but. a single embodiment of myinvention, it is to be understood that it is capable of manymodifications Changes, therefore, may be made which do not depart fromthe spirit and scope of my invention as disclosed in the appendedclaims.

I claim:

1. In mechanism of the class. described, means for gripping andsuspending a bag by its top comprising pairs of gripper jaws, the innerjaws being smooth and the outer jawsv roughened tomore firmly grip thebag, the jaws of each pair being pivotally mounted so that the jawsapproach each other as the outer jaw moves down.

with respect to the inner jaw whereby the weight of the bag tends tocause said jaws to more firmly grip the bag.

2. In mechanism of the class described, means for gripping andsuspending a bag by its top comprising pairs of gripper jaws, the innerjaws being smooth and the outer jaws being roughened, the outer jawbeing provided with an overhanging ear adapted to engage an inclinedupper portion of the inner jaw, the jaws of each pair being pivotallymounted with respect to each. other so that the weight of the bag tendsto cause the outer roughened jaw to slide down with respect to the.other so that the overhanging lip engages the inclined upper portion ofthe inner jaw to provide a wedging action to increase the grip: of the.jaws on the bag.

3. In. mechanism of. the class described, means for gripping andsuspending a bag by its top comprising pairs of gripper jaws, the innerjaws being smooth and. the outer jaws being roughened, the outer jawbeing provided with an overhang,- ing ear adapted to engage an inclinedupper portion of the inner jaw, the jaws of each pair being pivotallymounted with respect to each other so that the weight of. the bag tendsto cause theouter roughened jaw to slide down with respect to the otherso that the overhanging lipengages the inclined upper portion of theinner jaw to provide a wedging action to increase the grip of the jawson the bag, the jaws of each pair being, pivotally mounted so that thejaws approach each. other as the outer jaw moves down with respect tothe inner jaw whereby the weight of the bag tends to cause saidjaws tomore firmly grip the bag.

4. In mechanism of the class described, means; for gripping andsuspending a fiat object by itstop comprising a frame, a primary leverpivotally.- mountedthereon and having at its lower end afirst grippingjaw, a. secondary lever pivotally mounted eccentrically to the primarylever. and-- hingedly carrying a gripping jaw, the two levers beinggeared to oscillate in opposite directions to open and close thegripping jaws, and means operably connected to the primary lever forlocking the same in a position to grip a flat object between thegripping jaws.

5. In mechanism of the class described, means for gripping andsuspending a flat object by its top comprising a frame, a primary leverpivotally mounted thereon and having at its lower end a first grippingjaw, a secondary lever pivotally mounted eccentrically to the primarylever and hingedly carrying a bell-crank at its elbow, the lower leg ofthe bell-crank being pivotally connected to a second gripping jaw, theupper leg of the bell-crank being pressed by a spring that tends to urgethe second gripping jaw toward the first gripping jaw, the two leversbeing geared to oscillate in opposite directions to open and close thegripping jaws, and means operably connected to the primary lever forlocking the same in a position to grip a flat object between thegripping jaws.

6. In mechanism of the class described, means for gripping andsuspending a fiat object by its top comprising a frame, a primary leverpivotally mounted thereon and having at its lower end a first grippingjaw, a secondary lever pivotally mounted eccentrically to the primarylever and hingedly carrying a bell-crank at its elbow, the lower leg ofthe bell-crank being pivotally connected to a second gripping jaw, theupper leg of the bell-crank being pressed by a spring that tends to urgethe second gripping jaw toward the first gripping jaw, the two leversbeing geared to oscillate in opposite directions to open and close thegripping jaws, and means operably connected to the primary lever forlocking the same in a position to grip a flat object between thegripping jaws, the first jaw being smooth while the second jaw isroughened so that downward movement of the object gripped between thejaws moves the bell-crank and second jaw downward relatively to thefirst jaw to cause a greater grip between the jaws.

7. In mechanism of the class described, means for gripping andsuspending a flat object by its top comprising a frame, a primary leverpivotally mounted thereon and having at its lower end a first grippingjaw, a secondary lever pivotally mounted eccentrically to the primarylever and hingedly carrying a bell-crank at its elbow, the lower leg ofthe bell-crank being pivotally connected to a second gripping jaw, theupper leg of the bell-crank being pressed by a spring that tends to urgethe jaws toward each other, means on said jaws tending to urge the upperend of the second gripping jaw toward the first gripping jaw, the twolevers being geared to oscillate in opposite directions to open andclose the gripping jaws, and means operably connected to the primarylever for locking the same in a position to grip a flat object betweenthe gripping jaws.

8. In a mechanism of the class described, means for gripping andsuspending a bag by its top comprising a pair of gripper jaws, one jawpivoted below the point of gripping contact so that as the jaw movesdownwardly it will approach the opposing jaw, thereby more tightlygripping the bag as the bag moves downwardly.

9. A mechanism of the class described, means for gripping and suspendinga flat object by its top comprising a frame, means mounted thereoncarrying a first gripping jaw with a gripping face, carrying meansmounted on the frame and being movable from a non-gripping to a grippingposition, a jaw carrying member pivotally connected to said carryingmeans, a second gripping jaw having a gripping face abutting said firstjaw face in gripping position, said second jaw hingedly connected to thejaw carrying member to permit self-alignment of the jaw faces ingripping position, and spring means urging the jaw carrying member topivot in a direction to move the second gripping jaw toward the first.

10. In a mechanism of the class described, means for gripping andsuspending a bag by its top comprising a first and second jaw withopposing gripping faces, the first jaw having an upper inclined surfaceopposite the face and being fixed when in gripping position, a pivotalcarrying member connected to the lower portion of the second jaw andpivoted to cause movement of said lower portion toward the first jawwhen the jaw moves downwardly while in gripping position, and anoverhanging ear carried by the upper edge of the second jaw adapted toengage the inclined upper surface of the first jaw to provide a wedgingaction to increase the grip of the jaws on the bag as the second jawmoves downwardly with respect to the first.

11. A mechanism of the class described, means for gripping andsuspending a flat object by its top comprising a frame, means mountedthereon carrying a first gripping jaw with a flat gripping face, asecond gripping jaw having a fiat gripping face, and jaw carrying meansmounted on the frame and movable to carry said second jaw fromnon-gripping position to gripping position against said first jaw, thesec; ond jaw being hingedly connected to said jaw carrying means at apoint intermediate opposing edges of the gripping face to permitselfalignment of the faces of the first and second jaws in grippingposition.

HELMER ANDERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 141,186 Thomas July 22, 1873440,073 Tryon Nov. 4, 1890 1,019,366 Sargent Mar. 5, 1912 2,332,002Neuman Oct. 19, 1943

